Modular implant assembly tool
View Patent ↗This invention provides for a tool that produces, and directly and accurately measures, an axial force used to assemble two members of a modular implant, specifically, a modular hip implant.
1. An instrument for directly measuring an applied axial load, the instrument comprising:
first and second handles interconnected by a mechanical linkage and pivotally moveable toward one another;
two members moveable coaxially in opposite directions with respect to one another in response to movement of said handles, a first of the members being attachable to an item to which the axial load is applied, and a second of the members being moveable in the direction of the applied axial load;
a spring body positioned between the two members; and
a scale including at least one indicia mark to indicate the force applied to said spring body.
2. The instrument of claim 1 wherein said spring body comprises at least one compression spring.
3. The instrument of claim 1 wherein said spring body comprises at least one extension spring.
4. An instrument for directly measuring an applied axial load, the instrument comprising: first and second handles interconnected by a mechanical linkage and pivotally moveable toward one another;
two members moveable coaxially in opposite directions with respect to one another in response to movement of said handles, a first of the members being attachable to an item to which the axial load is applied, and a second of the members being moveable in the direction of the applied axial load;
a spring body positioned between the two members, and
a mechanism adapted to indicate when a predetermined force or displacement occurs in the spring body.
5. The instrument of claim 4 wherein said spring body comprises at least one compression spring.
6. The instrument of claim 4 wherein said spring body comprises at least one extension spring.
7. An instrument for directly measuring an applied axial load, the instrument comprising:
(a) two members that move coaxially in opposite directions with respect to one another, a first of the members being attached to the item to which the axial load is applied, and a second of the members which is moved in the direction of the relevant axial load;
(b) a piezoelectric element positioned between the first and second members; and
(c) a device for converting piezoelectric voltage into a signal indicating force being applied to said piezoelectric element.